In the field of the medium or large-size castings, traditional manufacturing methods with natural sands and subsequent drying processes have been mostly utilized. New mold materials have now been developed which permit a greater exactness in the sand mold manufacture. In the case of medium and larger castings, however, exposing the cast piece after casting is no longer sufficient for the demands of today for a logical operating process.
The safe control of the forces which occur during the casting process requires heavy flask parts, which are accordingly cumbersome to use. In order to provide closer measurement tolerances on the cast piece, the flask parts must be fixed and worked more exactly. One must thereby in addition consider that the unpacking of the cast pieces--the knocking out, exposing with removing tools, the shaking for unpacking, etc.--is still a rough method of operation and in addition illustrates an additional stress for the flask parts.
From all of these disadvantages results a high repair susceptibility and high expenses connected therewith, which makes impossible a competing of other working methods.
A sensible flask construction thus should not only assure a high stability and thus the goal of more close dimension tolerances, but is to contain also new possibilities for separating the flask and the sand mold after casting. As an important part of the set problem, a cleaning method for the flask parts must also be developed which is effective during separation in the interest of small forces.
The purpose of the invention is to increase the economy and produce an increase in production at a simultaneous increase in the preciseness of the finished work.
This is achieved with a flask of the above-mentioned type by inventively arranging in at least one part of the conical sidewalls of the flask frame holding-back baffle plates which are directed inwardly and can be tilted out or pulled out toward the outside of the mold.
With this one achieves a very much reduced outward power force onto the flask parts.